The synchronous buck switch-mode power converter is a commonly used topology for switch-mode power supply (SMPS) applications. The SMPS topology is gaining wider acceptance because of its high efficiency, small size and light weight. However, as the size of an SMPS is decreased, heat dissipation/removal therefrom becomes more problematic. Even though the typical efficiency of an SMPS may be 90 percent, there still remains 10 percent of the energy used by the SMPS becoming wasted heat. In addition, the high efficiency of the SMPS is optimized for only a single load condition. However, in real world applications power utilization loads vary over a wide range, and so do the associated SMPS efficiencies at those loads. Current sensing in the SMPS topology can be challenging and must be overcome in design. Knowing or monitoring the current being injected into the load provides protection for the power converter and can improve dynamic performance during closed loop control thereof.
Inductors in the SMPS are used to store energy during a portion of the switching cycle. The electrical characteristics, e.g., inductance and magnetic saturation values, of the SMPS inductor may vary widely. The tolerance of the inductor characteristics varies with temperature and/or voltage, so SMPS systems must be “over-designed” to optimize SMPS system efficiency for worst case conditions. Also, accurate measurement of the inductor current from one SMPS to another and at different load currents becomes problematic. Having the ability to accurately calibrate inductor current sense circuits associated with the inductors of a multiphase SMPS system would improve the dynamic performance and eliminate hot spots for the multiple phase converters of the multiphase SMPS system. In addition, having the ability to communicate with the SMPS system allows for operating parameters to be monitored, diagnostics to be performed, and operating objectives to be altered.